Table 3. CCD Matrixes for the Optimization of Diosgenin Yield.

				diosgenin yield (%)
run order	X1: period	X2: temp	X3: antifoam	predicted value	experimental value
1	–1	–1	+1	0.29	0.28 ± 0.079
2	+1	–1	–1	0.98	0.97 ± 0.123
3	0	0	0	1.95	1.94 ± 0.151
4	0	0	0	1.95	1.96 ± 0.157
5	0	0	0	1.95	1.92 ± 0.152
6	–α	0	0	0.25	0.27 ± 0.063
7	+1	+1	–1	1.99	1.98 ± 0.146
8	+1	–1	+1	1.31	1.30 ± 0.054
9	–1	–1	–1	0.34	0.33 ± 0.083
10	–1	+1	–1	1.03	1.02 ± 0.094
11	0	+α	0	1.10	1.11 ± 0.100
12	0	0	+α	1.56	1.58 ± 0.119
13	0	0	0	1.95	1.92 ± 0.112
14	0	0	0	1.95	1.97 ± 0.120
15	0	0	–α	1.70	1.71 ± 0.111
16	0	0	0	1.95	1.96 ± 0.166
17	–1	+1	+1	0.54	0.53 ± 0.083
18	+α	0	0	1.92	1.93 ± 0.131
19	0	–α	0	0.05	0.07 ± 0.029
20	+1	+1	+1	1.88	1.87 ± 0.117